HP Forum Archive 20

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Re: Voyager 1xC emulation in the same unit? Message #1 Posted by uhmgawa on 21 Jan 2012, 2:28 p.m. Exhuming this month old thread for context.. Quote: Quote: Message #15 Posted by uhmgawa on 22 Dec 2011, 5:24 p.m., Porting KEMU to the HP-12C+ or 15c le is relatively straightforward. But I'd be more interested to do so as part of a larger functional upgrade... in response to message #15 by uhmgawa That is a laudible goal which would be greatly appreciated, but I'm sure a lot of people would be very, very happy with a straightforward port, if you should ever be so inclined. What I had in mind was something like this, described in the latter part of the video. A KEMU port to a stock sam7 voyager isn't much of a technical hurdle. Rather the question of native firmware status is more of an issue, particularly for a multi-personality voyager.

Re: Voyager 1xC emulation in the same unit? Message #2 Posted by Bart (UK) on 23 Jan 2012, 5:27 a.m., in response to message #1 by uhmgawa Nice idea, however having multiple types on one unit presents problems with the keyboard. For functions not directly on the keys, an overlay would be fine of course, but how to change what's on the keys in an instant? I think it might be a better idea to buy multiple 15C LE units and re-program dedicated units and have overlays like for the WP-34s. There would of course be copyright issues, even if the code was not a copy of the HP ROM but entirely re-written, it would be a "copy-cat" issue - but HP would have the benefit of extra hardware sales.

Re: Voyager 1xC emulation in the same unit? Message #3 Posted by uhmgawa on 26 Jan 2012, 1:20 a.m., in response to message #2 by Bart (UK) Quote: Nice idea, however having multiple types on one unit presents problems with the keyboard. Indeed it does. The multi-firmware aspect was interesting (at least to me) from an experimental perspective. But the issue of key legends varying between models is a limitation, arguably offset by the partial solution of key legend support possible with a graphic display. Quote: For functions not directly on the keys, an overlay would be fine of course, but how to change what's on the keys in an instant? I think it might be a better idea to buy multiple 15C LE units and re-program dedicated units and have overlays like for the WP-34s. There would of course be copyright issues, even if the code was not a copy of the HP ROM but entirely re-written, it would be a "copy-cat" issue. Before going through that effort, there is the more fundamental missing feature of interoperation (minimally data exchange) between models. Adding it is certainly possible. However the time is far more productively applied to creating maintainable and extensible firmware -- an approach which can straightforwardly address not some, but all of the above.

Re: Voyager 1xC emulation in the same unit? Message #4 Posted by Jeff O. on 23 Jan 2012, 8:03 a.m., in response to message #1 by uhmgawa I can see that what you would like to do would be an improvement over a simple port to a sam7 voyager if the hardware were available. I would of course encourage the simple port, because the hardware is available (in my hands, even.) But with the concern over the legality of using the original rom images or reproducing their functionality, I could not blame you if you did neither.

Re: Voyager 1xC emulation in the same unit? Message #5 Posted by uhmgawa on 24 Jan 2012, 1:09 a.m., in response to message #4 by Jeff O. Quote: I can see that what you would like to do would be an improvement over a simple port to a sam7 voyager if the hardware were available. I believe I'd started down this slippery slope with a well intentioned push from WalterB [appreciated] in the course of discussing my KINOMI/NUT replacement project. Yet even if one could scare up a display retrofit, there are interconnect issues to resolve. And quite honestly the easiest way to address this is with a new board layout which is a relatively simple task. Well if we've got a new board layout it is difficult to resist adding the sorely missing functionality in that otherwise vacant PCB real estate. But wait, if we're creating a replacement board there really isn't any compelling reason to put an aged AT91SAM7L128 back into the design -- we could do considerably better with a more recent SoC. And having arrived at the foot of the slope, what are we really repurposing besides an ABS enclosure in a unique form factor? If we toss out that design constraint we no longer have the severe display retrofit limitation. Quote: I would of course encourage the simple port, because the hardware is available (in my hands, even.) Admittedly a valid argument exists there as the hardware is quite underutilized. Only about 25% of that 128KB flash is actually needed to contain the 15c legacy firmware and a NUT/Voyager emulator. Even the graphic voyager prototype depicted above with KEMU core, all of 11/12/15/16c rom images, multiple firmware support, serial console, graphic rendering, several fonts, demo cruft, etc.. doesn't even cross over 64KB on a C language challenged architecture. Add to this the idle resources present in the sam7 voyager and it is difficult to resist improving upon the design. Quote: But with the concern over the legality of using the original rom images or reproducing their functionality, I could not blame you if you did neither. Well, there is certainly precedence for releasing an emulator decoupled from its essential firmware. Yet doing so makes for somewhat of a poorly scaling proposition where each user needs to locate and program firmware images before a unit is functional.

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